Road machine



Oct. 1, 1940.

C. A. GUSTAFSQN ROAD MACHINE R0 Y m m NT s m u A, L

" Oct. l,

C. A. GUSTAFSON ROAD MACHINE Filed Dec. 20, 1933 3 Sheets-Sheet 2 E :1: E 'L U- INVENTOR.

CARL A. 61/5 TAF'SON A TTORNE Y.

atented Oct. 1, 1940 UNITED STATES ROAD MACHINE Carl A. Gustafson, Peoria, 111., assignor to Cater- .pillar Tractor 00., San Leandro, Calif., a corporation of California Application December 20, 1938, Serial No. 246,818

6 Claims.

My invention relates to road machines, and more particularly to power steering mechanism having special applicability to road graders of the self-propelled type.

Self-propelled graders are usually provided with front steering wheels and rear driving wheels; the machine being generally manually steered by manipulation of a manually controllable steering wheel connected through suitable steering mechanism to the front steering Wheels. If the gear reduction in the steering mechanism is relatively low to enable short turning of the steering Wheel to thus make steering quickly responsive to turning of the steering wheel, road shocks continuously cause the front wheels to deviate from a true course and the operator has to continuously steer the machine to maintain it on a proper course in order that the earth working means, such as the grader blade underneath the machine, may follow a true path. The operator of the machine, during working thereof, usually has to manipulate the usual earth working adjusting means on a machine of this character; and if he has to steer the machine at the 25 same time, this may interfere with his operation of the earth working adjusting means. Should the gear reduction in the steering mechanism be relatively high to preclude road shocks from causing the machine to deviate from a straight course, the above described difficulty is overcome, but steering requires more time and is more tedious because the steering wheel has to be turned more. Furthermore, even when the gear reduction is such as to enable steering by 35 short turning of the steering wheel, the steering becomes tedious when the machine is doing heavy duty work and traveling at-a slow speed, and this may impair the operators efliciency in adjusting the earth working means.

40 My invention is designed to obviate the above described difiiculties and has as its objects, among others, the provision of improved steering control means, particularly adapted for a self-propelled grader, which is designed to provide power steering for the usual steerable supporting means of such grader; which also allows manual steering when so desired; which is so constructed as to permit both power steering and manual steering by manipulation of the same control member 50 which is, preferably, in the form of the customary steering wheel; which, when power steering is employed to steer the machine, will not cause spinning of the control member and thereby possibly injure the operator; and which is of simple and economical construction, and easy to operate.

Other objects of the invention will become apparent from a perusal of the following description thereof. i

In general, the steering apparatus of my invention comprises selectively operable drive es- 5 tablishing mechanism which receives its power from the usual power plant or engine of the road machine, and which may be connected to rotate in either direction, a steering rod or shaft forming part of the steering mechanism or gear of the 19 machine. Control of the drive establishing mechanism is selectively effected by turning in either direction a manually operable steering wheel; a simple clutch mechanism being provided to connectsuch control means with the drive establishing mechanism when so desired. Means is provided to connect the steering wheel directly to the steering mechanism when it is desired to steer the machine manually; and when so connected, the drive establishing mechanism has no 20 driving effect or influence on the steering Wheel. Also, the drive establishing mechanism is so constructed that when connected to the steering mechanism for power steering, power is not transmitted to'the steering wheel to drive the same, thereby precluding spinning thereof which might injure the operator.

Reference will now be made to the drawings for a more detailed description of the invention in which: I

Fig. l is a more or less schematic side elevation of a self-propelled road grader equipped with the steering apparatus of my invention.

Fig. 2 is a fragmentary longitudinal sectional view, partly in elevation, illustrating the means for clutching the steering wheel for either manual or power steering.

Fig. 3 is a, plan view of the structure shown in Fig. 2, looking in a direction of line 3-3 in Fig. 2.

Fig. 4 is a vertical section taken in the plane 6 indicated by line 44 in Fig. 2. 1 f

Fig. 5 is a vertical section, taken in the plane indicated by line 5-5 inFig. 2.

Fig. 6 is a longitudinal vertical sectional view through the power operable drive establishing mechanism of my invention, taken in planesim di'cated by line 6-6 in Fig. 7.

Fig. 7 is a transverse vertical sectional view taken in planes indicatedby line 1-1 in Fig 6.

Fig. 8 is a horizontal sectional, view, partly in elevation, taken in aplane indicated by line 88 in Fig. 7.

Fig. 9 is a fragmentary sectional, plan view of a portion of the mechanism illustrated in Fig. 6, taken in a plane indicated by line 99 in Fig. 6.

Fig. 10 is a vertical sectional view through the main power control box on the grader, through which adjustable earth working means on the machine may be adjusted.

For the purposes of illustration, I have chosen a self-propelled grader of the type generally similar to that disclosed in my prior Patent No. 2,034,141, dated March 17, 1936, although my invention is applicable to any similar type of machine. Such grader comprises grader frame I mounted on front dirigible steering wheels 2 steerable through any suitable steeringgear or mechanism, and on rear tandem drive wheels 3 driven from the engine 4. Grader blade 8 is mounted for angular adjustment, on the usual rotatably mounted circle mechanism 1 supported on drawbar mechanism 8 which has a universal front draft connection (not shown) at the front of grader frame I, and which is suspended at its rear from the grader frame I by means of adjustable lift links 9, connected to rotatable crank arms ID by which either end of blade 8 may be adjusted vertically. By such means, the usual adjustments provided in graders may be imparted to the earth working grader blade 6.

The adjustments-in the machine chosen for purposes of illustration are preferably power controlled by suitable clutch mechanism drivable from the engine and otherwise of the type described in my aforementioned patent. As I preferablyderive power from the engine through-such clutch mechanism for the power steering, a brief description of such clutch mechanism is made herein. The clutch mechanism comprises a plurality of reversibly operable clutch assemblies grouped within a common housing I I, located adjacent the operator's station |2 of the machine. One of such assemblies is illustrated in Fig. 10 and comprises oppositely positioned bevel gears |3 journaled about shaft l4 journaled in housing ll; each of gears l3 having integral therewith a spur gear IS. The bevel gears |3 mesh with a bevel gear l8 secured to upright shaft which is continuously power driven from the engine, in the manner illustrated in my previously mentioned patent. It is thus seen that bevel ears |3 are continuously rotated in opposite'directions; and by means of a clutch element l8, splined for rotation with shaft l4 and axially shiftable to engage either gear |3 by proper manipulation of control handle |3 connected to clutch control fork 28 which engages clutch element i8, shaft |4 may be selectively rotated in either one of opposite directions when so desired, to effect adjustment of the mechanism which may be connected to such shaft H. The spur gears Ii mesh with similar spur gears journaled about a shaft forming part of an adjacent clutch assembly, to thus provide a plurality of adjusting mechanisms, as is disclosed in my patent.

As previously mentioned, I utilize the continuous power imparted to the clutch control mechanism for the power steering. This is obtained by shaft 2| journaled in housing H, and continuously driven from the left-hand continuously driven bevel gear |3 appearing in Fig. 10 by means of the spur gear l5 integral with bevel gear l3. and which also engages a spur gear 22 integral with shaft 2|.

Means is provided for transmitting continuous power from continuously rotated shaft 2|. to the selectively operable power steering drive establishing mechanism adapted for connection to the steering gear or mechanism. With reference to Figs. 1, 6 and 10, shaft 2| is connected by sleeve 23 to shaft 24 which has a universal connection 26 with a shaft 21 journaled in the lower part of drive establishing or clutch housing 28 mounted on grader frame I. Shaft 21 has formed integral therewith a wide pinion 29 which engages and continuously rotates in one direction a gear 3| which is journaled on a shaft 32 for rotation about such shaft: shaft 32 being journaled for rotation in housing 28. A second gear 33 spaced from gear 3| is also journaled on shaft 32 for rotation about the shaft, and is driven continuously in a direction opposite to gear 3|, by means of reverse gearing journaled in the housing 28 and which includes shaft 34 having at one end thereof gear 36 engaging pinion 29 and at the opposite end gear 31 engaging gear 33.

It is to be noted that gears 3| and 33, although continuously rotated in opposite directions, do not by such rotation drive shaft 32. Control means is provided -to connect either of gears 3| or 33 to shaft 32, to thus cause such shaft to be rotated in either one of opposite directions for driving the steering mechanism in either one of opposite directions. A clutch element 38 rotatable with shaft 32 and axially shiftable in either direction along such shaft, by virtue of the splined connection 38, is provided at each end with beveled clutch teeth 4| (Fig. 9) adapted to engage complementary clutch teeth 42 on gears 3| and 33. When such clutch element 38 is shifted so as to be clutched to gear 3|, shaft 32 will be rotated in one direction; and when the clutch element 38 is connected to gear 33, shaft 32 will be rotated in the opposite direction. Axial shifting of clutch element 38 is effected by means of fork 43 integral with sleeve 44 and engaging in a groove 46 formed in clutch element 38; sleeve 44 being loosely mounted about a sleeve 41 keyed so as to be secured for rotation with elongated tubular member or sleeve 48 which may be turned in either direction by a steering control wheel, in a manner to be subsequently described.

A pin 49, fixedly secured to sleeve 44, engages a helical slot 5| formed in the sleeve 41 which is keyed to sleeve 48. By such engagement of pin 43 in helical slot 5|, sleeve 44 may be made to travel in either one of opposite axial direc tions, depending upon the direction of turning of elongated sleeve 43, to thus cause clutch element 38 to be shifted in either one of selected opposite directions, and thereby cause shaft 32 to be rotated in either one of opposite directions.

Shaft 32 is connected to steer the front steering wheels 2 of the machine when operated in the selected direction through the described drive establishing mechanism, by means of pinion 52, secured for rotation with shaft 32 and engaging a gear 53 secured for rotation with elongated shaft 54 which extends completely through the elongated sleeve 48 and through housing 28. At its forward end, shaft 54 is connected, by means including sleeve member 53, to shaft ll journaled in a suitable bracket 53 on the main frame I of the machine; shaft 51 forming part of the steering mechanism and being connected by universal connection 58 to a shaft 6|in turn connected through universal connection 62 to the remainder of the steering mechanism for the steering wheels 2, which may be of any conventional or suitable construction and generally includes worm and worm wheel connection 83.

From the preceding description, it is seen that when clutch element 33 is in neutral position,

power steering does not occur, but when clutch element 38 is shifted to engage either of gears 3| or 33, the front steering wheels 2 may be turned in either direction depending upon the direction of shifting of clutch element 88. In this connection, shaft I1 is continuously rotated in such direction, that when the steering control means including sleeve 48 is turned to the right or left, the steering wheels will be turned to the right or left, respectively. By virtue of the beveled character of clutch teeth 4| and 42, there is no danger of injuring the mechanism should the operator cause the steering wheels to be turned to the maximum extent, and still have the drive establishing mechanism in engagement, because such clutch teeth provide a camming action which causes the clutch teeth to disengage automatically.

Means is provided in housing 28 to maintain resiliently the clutch element 38 in neutral position comprising laterally extending ears 54 on sleeve 44, each of which is provided with an aperture 65 adjacent its end. A rod 61, fixedly secured in housing 28, extends through each aperture 6B in ear 64; and a spring 68 is interposed between each side of each ear64 and the adjacent side of housing 28. Thus, when elongated sleeve 48 is turned to effect shifting of clutch element 38, and subsequently released, the resilient means 68 will restore the mechanism including the sleeve 48, to neutral position. At the same time, since ears 54 engage the fixed rod 61, only axial movement will be imparted to sleeve 44 when sleeve 48 is turned, to provide the results previously discussed.

Means is provided in the form of a. hand operated steering wheel to effect turning of sleeve 48 to actuate the power steering drive establish- Will ing mechanism, in the manner described, and also to permit optional manual steering by direct turning ofshaft 54, when so desired. With particular reference to Figs. 1, 2 and 3, sleeve 48 extends to the operators station 12 of the machine, and is journaled adjacent its rear end in a suitable bearing ll pivotally mounted on bracket 12 supported on clutch housing H. Elongated shaft 54, which extends all the way through sleeve 48, is journaled adjacent'its rear end in a suitable bearing 73 in sleeve 48, and projects beyond the rear end of the sleeve to the operators station. Hub 14 of manually controllable steering wheel 18 is journaled for free rotation about the projecting end of shaft 54, and is formed with a longitudinally extending slot 11, in which is pivotally mounted on a bolt 11', an L-shaped latching member or clutch element 18 having a latching tooth 19 at one end thereof and another latching tooth 8! at its opposite end.

Latching member 18 is resiliently pressed so that either one of its legs is maintained in a substantially horizontal position for a purpose to be subsequently explained, by means of a flat spring element 82, mounted in a recess, in hub 14. A control handle 84 is formed integral with latchingmemberv 18': to permit latching tooth 8|, to be shifted so, asto engage in a recess 88 formed. in collar 81 fixedly'clamped to the rear end-of sleeve 48,,to enable. such sleeve to be turned in either one of opposite directionsby wheel 18.

, vAscaii be seenfrom 5, collar 81 is split, has

a keyedconnection 88 with sleeve 48, and is also rigidly clamped to the sleeve by means of bolt and nut connection 89, to thus provide a rigid connection with the sleeve. Also, latching member 18 may be shifted by control handle 84 to engage latching tooth 18 in a recess 8| formed in collar 82 rigidly secured to the rear end of shaft 54, by means including key 83 and nut 84. In 1 turn steering wheel 16 a few degrees to the right.

or the left, whichever may be desired, and hold it there, to effect corresponding steering of the steerable front wheels 2 in the manner already described. Upon release of steering wheel 18, when the desired power steering is effected, wheel 18 will be immediately restored to neutral position, as well as clutchelement 38, by virtue of the resilient means 88. Although shaft 54 is rotated during the power steering, it is to be noted that under such conditions, there is no connection of shaft 54 with wheel l6. Hence no spinning of such wheel, which might cause injury to the operator, can occur. Also, since the power steering control means including wheel 16 and sleeve 44 is not 'driven when connected to esstablish a drive through the described drive esstablishing mechanismbut only serves as a control means, no spinning of steering wheel 16 can occur during the power steering. The power steering enables the machine to be steered quickly and easily thus leaving the operator more time for adjustments of the earth Working means, and therefore facilitates his work in this respect.

When it is desired to employ hand steering, for example when the machine is traveling at a comparatively high speed and not doing work, latching member 18 may be shifted to cause engagement of wheel 16 with shaft 54, and disengagement from tubular sleeve 48; and in turning the hand wheel 16, it will effect steering in a normal way through shaft54. In this connection, it is to be observed that when hand steering is employed, shaft 54 will not be driven through the drive establishing mechanism, because sleeve 48 and consequently clutch element 38, being free of connection with wheel 16, will be held in neutral position by resilient means", and shaft 32 will not be engaged with either of gears 3| and 33. The provision of the single hand controllable steering wheel 16 for effecting. the power steering as well as the hand steering, is desirable because it places no extra burden on the operator; the 'same manipulations being all that is necessary in both cases. i

I, therefore, claim as my invention: 1. A self-propellable' vehicle having a'source of power: steerable ground engaging supporting means fors'aid vehicle steering mechanism for said ground engaging supporting means; shafting connected to said steering mechanism and adaptedto be rotated in either one of opposite directions to effect steering in; either "one of oppositedirections: jdrive establishing mechanism for effecting power steering of said steering mechanism in either one of opposite directions comprising a normally stationary shaft connected to said shafting so as to drive the same when it is driven, a pair of gears journaled about said shaft and having beveled clutch teeth on the inner faces thereof, means connected to said source of power for driving said gears in opposite directions, and a clutch element rotatable with and axially shiftable in either direction along said shaft and having beveled clutch teeth adapted to engage said first mentioned clutch teeth to connect either of said gears to said shaft to drive said shaft in either one of opposite directions; and control means for shifting said clutch element.

2. A self-propellab-le vehicle having a source of power; steerable ground engaging supporting means for said vehicle; steering mechanism for said ground engaging supporting means; shafting connected to said steering mechanism and adapted to be rotated in either one of opposite directions to effect steering in either one of opposite directions; a tubular shaft through which said shafting extends; drive establishing mechanism for effecting power steering of said steering mechanism in either one of opposite directions comprising a normally stationary shaft connected to said shafting so as to drive the same when it is driven, a pair of gears journaled about said shaft, means connected to said source of power for driving said gears in opposite directions, and a clutch element rotatable with and axially shiftable in either direction along said shaft to connect either of said gears to said shaft to drive said shaft in either one of opposite directions; control means for shifting said clutch element including said tubular shaft which is turnable in either one of opposite directions and which extends from said drive establishing mechanism, connecting means between said Qtubular shaft and said clutch element, and a manually operable steering wheel free of but connectable to said tubular shaft for effecting turning of said tubular shaft; means for optionally enabling manual steering of said steerable steering mechanism including said shafting extending through said tubular shaft and said steering wheel which is also free of but connectable to said shafting; and means for selectively connecting said steering wheel to said shafting or to said tubular shaft.

3. A self-propellable vehicle having a source of power, steerable ground engaging supporting means for said vehicle, steering mechanism for said steerable ground engaging supporting means adapted to be selectively power or manually driven in either one of opposite directions, drive establishing mechanism drivable from said source of power to transmit a selected power drive to said steering mechanism in either one of opposite directions, control means for said drive establishing mechanism including a tubular shaft turnable in either one of opposite directions, a steering wheel journaled about an axis for free rotation, optional control means for manually steering said steering mechanism including shafting extending through said tubular shaft and connected to said steering mechanism, and means for selectively connecting said steering wheel to said shafting or to said tubular shaft.

4. In a self-propellable vehicle, a source of power, steerable ground engaging supporting means for said vehicle, steering mechanism for said steerableground engaging supporting means adapted to be selectively power or manually driven in either one of opposite directions, drive establishing mechanism drivable from said source of power to transmit a selected power drive to said steering mechanism in either one of opposite directions, a tubular shaft and another shaft extending through said tubular shaft, one of said shafts being connected to said drive establishing mechanism and being turnable in either one of opposite directions to control said drive establishing mechanism and the other shaft being connected to said steering mechanism for manual steering thereof, a steering wheel journaled for free rotation, and means for selectively connecting said steering wheel to either of said shafts.

5. A vehicle having an engine; a member continuously driven by said engine; steering mechanism for said vehicle; drive establishing mechanism for actuating said steering mechanism including a shaft adapted to be rotated in either one of opposite directions to effect steering of said steering mechanism in either one of opposite directions, a pair of gears journaled about said shaft and connected to said continuously driven member for constant rotation in opposite directions, said gears having clutch teeth on the inner faces thereof and a clutch element rotatable with and axially shiftable from a neutral position in either direction along said shaft and having clutch teeth adapted to engage said first mentioned clutch teeth to connect either of said gears to said shaft; control means for shifting said clutch element comprising a member tumable in either one of opposite directions and extending from said drive establishing mechanism, and a manually controllable steering wheel for effecting turning of said turnable member; and means for automatically restoring said clutch element to neutral position when said manually controllable steering wheel is released,

6. A vehicle having an engine; a member continuously driven by said engine; steering mechanism for said vehicle; drive establishing mechanism for actuating said steering mechanism including a shaft connected to said steering mechanism and adapted to be rotated in either one of opposite directions to effect steering of said steering mechanism in either one of opposite directions, a pair of gears journaled about said shaft and connected to said continuously driven member for constant rotation in opposite directions, and a clutch element rotatable with and axially shiftable in either direction along said shaft to connect either of said gears to said shaft; control means for shifting said clutch element comprising a tubular shaft turnable in either one of opposite directions and extending from said drive establishing mechanism, connecting means between said tubular shaft and said clutch element, and a manually operable steering wheel free of but connectable to said tubular shaft for effecting turning of said tubular shaft; means for optionally enabling manual steering of said to said turnable shaft; and means for selectively connecting said steering wheel to said turnable shaft or to said tubular shaft.

, CARL A. GUSTAFSON. 

